The present invention relates to a new and distinct cultivar of Begonia, of the family Begoniaceae, and given the cultivar name, ‘Garden Angel Plum’. This plant originated from planned breeding program for a colorful series of landscape Begonia. The new cultivar originated from a cross between Begonia ‘Benitochiba’ (unpatented), as the seed parent, and Begonia grandis subsp. evansiana (unpatented), as the pollen parent. This selection is uniquely characterized by:                1. maple-like palmately lobed leaves with showy interveinal silvering turning plum in warm temperatures,        2. red leaf backs,        3. a bushy habit,        4. small clusters of large bright pink flowers in winter to early spring,        5. hardy to USDA Z7, and        6. excellent vigor.        
Compared to the seed parent Begonia ‘Benitochiba’, an unpatented plant, the new cultivar has leaves that are palmately lobed rather than palmately compound. The new cultivar is hardy rather than being a tropical plant.
Compared to the pollen parent, Begonia grandis subsp. evansiana (an unpatented plant with the common name, Hardy Begonia), the new cultivar has leaves that are palmately lobed rather than no lobes and with strong interveinal silvering rather than no silvering.
Compared to Begonia ‘Garden Angel Blush’ (U.S. Plant patent application Ser. No. 13/986,504), the new cultivar is taller with the leaves colored plum in warm temperatures rather than having a plum-red violet blush.
Compared to Begonia ‘Garden Angel Silver’ (U.S. Plant patent application Ser. No. 13/986,505), the leaves of the new cultivar have interveinal silvering that turns plum in warm temperatures rather than staying silver.
The new variety has been reproduced only by asexual propagation (cuttings and tissue culture). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by micropropagation as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.